1. Field of the Invention
This invention relates to a sensor that detects a position of an object. More specifically, the invention relates to a sensor that senses the object position by detecting the presence or absence of a fluid flow.
2. Description of Related Art
Sensors are typically used to detect the position of various objects. A sensor may be positioned adjacent to a passage through which an object passes or adjacent to an area in which an object is positioned.
An illustrative example of an apparatus in which a sensor is used to detect an object's position is a photocopy device. Typically, in a photocopy device, multiple paper sheets are stored in a paper storage bin. Upon initiating a copying operation, a sheet is transported from the paper storage bin through various paths in the photocopy device. For example, the sheet is transported via a specified path to an area in which an image is reproduced on the paper. Thereafter, the sheet is transported via additional paths to a recovery bin from which the sheet can be retrieved.
Monitoring the position of each sheet as it passes through the various paths is integral to the operation of the photocopier. Various conventional sensors are currently used to detect the object's position in a conventional photocopier. For example, one conventional device for detecting the position of a paper sheet includes a light source and light sensor arrangement. This device may include a light emitting diode (LED) and a photodiode pair, wherein the light source emitted from the LED is eclipsed as the paper sheet moves between the light source and the light sensor.